Y1DA--630A4-26-401 MRI AHU Modification

36C24226R0060
Amendment 3
630A4-26-401 MRI AHU Modification

6. Per our teams meeting this morning, please see below RFI's;

There are 3 potential options for the MRI chiller:
Air cooled package at grade with glycol and pump package.
Air cooled package at grade using glycol but also using a plate and frame heat exchanger to separate the glycol from the clear water.
Air cooled split chiller with outdoor condenser and indoor evaporator using clear water only.

Does The VA have a preference for which system works better for them?

The scope of work calls for an inline pump to serve the fan coil units. Can the VA share the reason for these extra pumps as series pumping can present issues. If the additional head is included in the new chiller pumps does that suffice?

There are 6 new fan coil units called for in the corridor. This is 9 tons of cooling. Does the corridor have that kind of a load? Typically, corridors are only lighting and a few transient people. Also, if 9 tons is used for fan coil units, is 21 tons sufficient for the MRI Load?

COR answer(s):
It appears that Option 2 may be the more effective choice; however, as this is a design-build project, we rely on the A/E team s expertise to design the system in accordance with VA requirements and specifications.
Accordingly, a series pump configuration is not considered an acceptable design.
The A/E team should perform its own heat load calculation for the corridor to determine the required cooling capacity. The VA has provided only general information; it is the contractor s design team s responsibility to determine the actual requirements and verify whether the chiller recommended by the VA is sufficient.